import javax.servlet.ServletException;
import javax.servlet.annotation.WebServlet;
import javax.servlet.http.HttpServlet;
import javax.servlet.http.HttpServletRequest;
import javax.servlet.http.HttpServletResponse;
import javax.servlet.http.HttpSession;
import java.io.IOException;

@WebServlet("/index")
public class IndexServlet extends HttpServlet {
    @Override
    protected void doGet(HttpServletRequest req, HttpServletResponse resp) throws ServletException, IOException {
        //返回一个主页，一段html片段
        //此处getSession的参数必须时false，前面在登录过程已经创建过会话了
        HttpSession session = req.getSession(false);
        String username = (String) session.getAttribute("username");

        //从会话里取出count
        Integer count = (Integer) session.getAttribute("count");
        count+=1;
        //把自增之后的值写回到会话之中
        session.setAttribute("count",count);

        resp.setContentType("text/html; charset=utf8");
        resp.getWriter().write("<h3>欢迎你"+ username+"这是第"+count+"访问主页"+"</h3>");

    }
}
